This research is directed toward understanding the mechanism of action of monomeric growth hormone in basic and clinical setting. Current projects are as follows: 1. An evaluation of the biological response of isolated hepatocytes to rat and human growth hormone. The uptake of C14 to deoxyglucose, aminobutyric acid and the incorporation of leucine into protein are being studied as possible biological responses of growth hormone. This study should delineate the affects of a prolactin (human growth hormone) and a somatotropic hormone (rat growth hormone) on the isolated hepatocytes. 2. Comparison of human growth hormone, rat growth hormone, ovine prolactin and rat prolactin binding to isolated rat hepatocytes and liver cell membranes. The binding of these iodinated hormones to liver cell membranes and isolated hepatocytes is being studied to determine the nature of the receptor for somatogenic and lactogenic hormones on liver tissue. The displacement properties and effects of pH and cations on the binding are being used to distinguish characteristics of the individual hormone binding. 3. Effect of hypophysectomy and hormone replacement on alkaline RNase activity in rat liver and kidney subcellular fraction. Alkaline RNase activity is noted to be increased in hypophysectomy. We are studying the effect of hypophysectomy starvation and individual hormone replacements in hypophysectomized rats on the alkaline RNase activity of rat liver and kidney subcellular fractions. 4. Evaluation of the immunocompetence of patients with growth hormone deficiency.